1. Technical Field
The present disclosure relates generally to a coring device for surgical use. More specifically, the present disclosure relates to a coring device having an advanceable member operated at a coordinated speed to facilitate reproducible coring of body tissue. The coring device is particularly suited for use in performing transmyocardial revascularization (TMR).
2. Background of the Related Art
Mechanical coring devices suitable for use in surgical procedures such as biopsy retrieval, bone marrow retrieval, and similar procedures are well known. Typically, these coring devices include a tubular body having a sharpened end, and a cutting member. During coring procedures, the tubular body is manually advanced into body tissue such that a core of material is retrieved and retained within the tubular body. Thereafter, the cored tissue is removed for analysis.
One problem associated with these devices is that variations in the rate of advancement of the tubular body into the body tissue effect the size and shape of the cored tissue sample, e.g., a high rate of advancement can cause tearing of body tissue rather than precise coring of the tissue. Because of this, manual advancement makes it very difficult to retrieve good tissue samples of consistent size and shape required for biopsy. U.S. Pat. No. 4,461,305 issued to Cibley, addresses the problem of obtaining more consistent tissue sample sizes. Cibley discloses a biopsy device having a rotatable shaft with a cutting edge at its distal end. As the shaft is rotated, a trigger is compressed to manually advance the shaft into body tissue. Although Cibley improves upon the prior art, the performance of Cibley's device is directly related to the rate at which the shaft is manually advanced into the body tissue. Because the shaft is manually advanced, reproducible coring for the particular body tissue is difficult to achieve.
Mechanical devices have also been used in other surgical procedures. One such procedure is Transmyocardial Revascularization (TMR). In this procedure, surgical needles, biopsy needles, cannulas or similar instruments have been used to produce channels from the epicardium, through the myocardium and into the ventricle of the heart. It is believed that these channels facilitate delivery of blood directly from the ventrical to the oxygen starved areas of the heart. When performing a TMR procedure, 1 or more and typically dozens of channels are created in the heart. Because heart tissue has a soft, spongy texture that can be easily torn or deformed, it is difficult, if not impossible, to create consistent, reproducible channels by the aforementioned manual puncturing and coring techniques.
Accordingly, a need exists for an improved mechanical coring device that is easy to use, consistent and reliable when coring channels in body tissue.